<p>Soil microorganisms are essential for sustaining ecosystem functions, driving biogeochemical cycles, and modulating carbon storage. However, the nutrient-mediated mechanisms by which different land-use types shape soil microbial communities remain unclear. This study investigated three typical land-use types—plantation, grassland, and high-standard cropland—in Xinyang City, China, to evaluate their effects on soil microbial community. Results showed that soil nutrient contents—including total nitrogen, total phosphorus, alkaline-hydrolyzable nitrogen, and available phosphorus—as well as microbial alpha diversity indices, were consistently higher in topsoil than in subsoil and more pronounced in plantation than in grassland and cropland. Acidobacteriota, Pseudomonadota, Ascomycota, and Basidiomycota dominated across all land uses, though community composition varied significantly among them. Network analysis revealed strongest microbial connectivity in plantation, intermediate in grassland, and weakest in cropland. Our findings demonstrate that land-use type and soil depth directly affect soil available nutrients, thereby influencing microbial diversity. This study clarifies the nutrient-driven pathways through which land use affects soil ecosystems, providing important insights for sustainable land management and ecological conservation.</p>